the first thing that shows up is that the 'historic averages' are not uniform across cities, with sydney always been above 5, with both melbourne a nd sydney being above 6 in 2001, while the other cities were 4. since then there has been a rise to around 7 for all cities except sydney which is 8.
If you consider that that there has been a trend upwards, even before the so called 'cheap credit situation' the current moves to 7-8 are the aberations.
This is all great and can mean something to a 50 plus single professor who rents, but has anyone used any of these stats to actual determine when to buy and sell or are these stats just talking points for renters as a means to justify their basis for not investing in real estate.
I reviewed the demographia stats several years ago to see which cities in the US were undervalued as I was interested in ionvesting there. This was just prior to hurricane Katrina. I thought new orleans provided good returns. New orleans was very cheap, but on further reseach there were speicific reasons including the way taxes effect the averages and how they effect rental return and the demographics of the people living their and the quality of housing. however, with out understanding the actual dynamics of a city the demographia stats were useless.
I personally review each location when I build/invest to detemrine the profitability, rather than stats etc.
An example was the Hervey Bay property I referred to earlier. For this i would look at why people will move there, why people would pay $600K plus for a home, what they want, is it upwardly mobile, shortage or availibilty of land, things going on in the local ie new harbour development, sea change influences etc.